This paper talks about the synthesis and structural characterization of four kinds of imidazolium compounds.The method of fluorescent spectra is adopted to study the selective recognition of Cyclophane for guest molecule (nucleoside,nucleotide).The results show that the tetra imidazolium 5,7 have a good recognition of nucleoside and nucleotide whereas bisimidazolium is better at recognizing I- ion. Through 1HNMR titration study of cyclophane 5 with GTP and Dribose,it is found that the hostguest recognition site is possibly based on the sugar unit of GTP.